Which zone is commonly called the Twilight Zone?

Which zone is commonly called the Twilight Zone?

• A. Mesopelagic zone
• B. Bathypelagic zone
• C. Abyssopelagic zone
• D. Hadopelagic zone

Answer: (A)

The Twilight Zone is the mesopelagic zone, the mid-depth part of the ocean where light is present but very faint. This layer lies below the sunlit photic zone, roughly from about 200 meters down to around 1,000 meters. The light here is too weak for photosynthesis, so organisms adapt to dim conditions, often using bioluminescence and relying on prey from above or on vertical migrations to the surface at night for feeding. Beyond this zone lie the deeper, completely dark layers—the bathypelagic, abyssopelagic, and hadopelagic—each deeper and darker than the last.

The Twilight Zone is the mesopelagic zone, the mid-depth part of the ocean where light is present but very faint. This layer lies below the sunlit photic zone, roughly from about 200 meters down to around 1,000 meters. The light here is too weak for photosynthesis, so organisms adapt to dim conditions, often using bioluminescence and relying on prey from above or on vertical migrations to the surface at night for feeding. Beyond this zone lie the deeper, completely dark layers—the bathypelagic, abyssopelagic, and hadopelagic—each deeper and darker than the last.